INTRODUCTION:

One of the most important groups of a biochemically Pyridine and its derivatives are chemical compounds which have different applications in various fields. Pyridine derivatives having different activities like Anti-oxidant¹, Anti-microbial and they used for the treatment of dermatitis and dementia². Pyridine is the basic heterocyclic compound consists of nitrogen in six membered rings. The structure of pyridine same as benzene only one difference between benzene and pyridine. Chalcones are synthesized with the help of aldehyde, ketone and base. It consist two benzene ring with ketone group. The reaction by which chalcone synthesized was claisen schmidt condensation. These are also obtained naturally from flavanoids. Many flavanoids contain various chalcone that are directly collected without any synthetic process³. Chalcones are also called alfa, beta-unsaturated ketones, benzal acetophenones, benzylidine acetophene, beta-phenylacrylophenone etc. There are various activities of chalcones like antitumor^4,5, antispasmodic⁶, antiulcer^7,8, antihelmintics^9,10, antibacterial¹¹, cardiovascular¹², antiallergic¹³, anticancer^14,15, germicidal¹⁶, insecticidal^17,18 and herbicidal¹⁹. Anti-inflammatory^20,21,22, analgesic^23,24, antioxidant^25,26, antimalarial²⁷, antiviral^28,29,30,31, antidiabetic^32,33. The chalcones are open-chained molecules is two aromatic rings, which are joined by three carbon chains containing an, β-unsaturated bond and a carbonyl group^34,35,36. Pyridine derivative have different pharmacological activities that are anti-microbial, anti-epileptic, anti-oxidant, anti-diabetic activities^{37,38,39,40,41}. The first pyridine base was isolated by Anderson in 1846. The structure of pyridine was determined by Wilhelm Korner in 1869 and James Dewar in 1871. Herein, we report the synthesis, spectral characterization, molecular docking, DFT studies and biological evaluation of N-(2-oxo-2-(phenylamino)ethyl) picolinamide derivatives as anti-inflammatory and antidiabetic activity.

MATERIALS AND METHODS:

Experimental:

All chemicals, solvents and reagents were purchased from spectrochem, TCI chemicals, Sigma-Aldrich (AR grade). Reaction progress was monitored by thin-layer chromatography on 0.2mm precoated aluminum sheet Silica Gel Merck 60 (F254). Melting points of the synthesized compounds were determined by open glass capillary tubes and are uncorrected. FT-IR spectrum of all the products was recorded on PerkinElmer FT-IR-4400 using KBr pellet technique. Proton ¹H NMR and ¹³C NMR spectra were recorded on Bruker Avance spectrometer 400 MHz and 100 MHz respectively, DMSO-d₆ or CDCl₃ solvents using tetra methylsilane (TMS) as the internal standard. Chemical shift values are given in δ (ppm) scale and the signals are described as s (singlet), d (doublet), t (triplet), q (quartet) and m (multiplet), whereas coupling constants (J) are expressed in Hz. Mass spectra (ESI-MS) were recorded on SHIMADZU mass spectrometer.

Typical experimental procedure for the synthesis of ethyl 2-(picolinamido) acetate:

The 2-picolinic acid (1a) and ethyl 2-aminoacetate (2a) was dissolved in acetonitrile. The solution, TBTU and triethylamine was added. The reaction mixture was stirred for 30 min and then glycine ethyl ester was added. The reaction mixture was stirred for 4 hours and the completion of reactant was monitored by TLC method. The reaction mixture was diluted with ethyl acetate, washed with sodium bicarbonate solution, water and brine solution. The organic layer was separated and dried over anhydrous sodium sulfate. The ethyl acetate layer was separated and concentrated under vacuum and the concentrated product was purified by column chromatography on silica gel (Merck, 200-400 mesh, ethyl acetate/petroleum ether, 1:4) to give the products ethyl 2-(picolinamido) acetate (3a) in 68.0 % yield.

FT- IR (KBr) V_max cm^-1: 3321, 1713, 1693, 1633, 1441, 1229, 1114, 708; ¹H NMR (CDCl₃, 400 MHz) δ: 8.59 (d, 1H), 8.50 (brs, 1H, NH), 8.17 (d, 1H), 7.87 (d, 1H), 7.83 (d, 1H), 4.23 (q, 4H), 1.29 (t, 3H); ¹³C NMR (100MHz, CDCl₃) δ: 169.2, 161.7, 151.1, 147.2, 137.0, 126.8, 121.3, 61.2, 40.8, 14.1; MS: m/z: 208 (M⁺); Anal. Calcd. for C₁₀H₁₂N₂O₃: C, 57.68; H, 5.81; O, 23.05; Found: C, 55.60; H, 5.67; O, 22.20.

Typical experimental procedure for the synthesis of 2-(picolinamido) acetic acid:

The ethyl 2-(picolinamido) (3a) acetate was dissolved in methanol to that solution sodium hydroxide was added as aqueous solution and stirred for 30min. The completion of the reaction was monitored by thin layer chromatography technique. The methanol is evaporated and diluted with water. The aqueous layer was washed with ethyl acetate. The acidification of the aqueous layer gives white precipitate which filtered and dried. The products 2-(picolinamido) acetic acid (4a) in 65.0 % yield.

FT- IR (KBr) V_max cm^-1: 3338, 1700, 1690, 1648, 1470, 1232, 1124, 714; ¹H NMR (CDCl₃, 400 MHz) δ: 12.68 (s, 1H, COOH), 9.00 (d, 1H), 8.68 (d, 1H), 8.05 (d, 2H), 7.64 (t, 1H), 3.99 (s, 2H); ¹³C NMR (100MHz, CDCl₃) δ: 172.7, 161.5, 151.1, 147.2, 137.8, 126.3, 121.4, 40.9; MS: m/z: 180 (M⁺); Anal. Calcd. for C₈H₈N₂O₃: C, 53.33; H, 4.48; O, 26.64; Found: C, 50.64; H, 4.77; O, 26.20.

Typical experimental procedure for the synthesis of N-(2-oxo-2-(phenylamino)ethyl) picolinamide derivatives

The 2-(picolinamido) acetic acid (4a) was dissolved in acetonitrile solution, TBTU and triethylamine was added. The reaction mixture is stirred at ambient temperature for 30 min. To that solution corresponding amine was added and the stirring continued for 4h, the completion of the reaction is tested using TLC method. The reaction mixture was diluted with ethyl acetate, washed with sodium bicarbonate, water and brine solution. The organic layer is separated and dried over anhydrous sodium sulfate. The ethyl acetate layer was separated and concentrated under vacuum and the concentrated product was purified by column chromatography on silica gel (Merck, 200-400 mesh, ethyl acetate/petroleum ether, 1:4) to give the products N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives (5a-c) in 88.0 % yield.

N-(2-oxo-2-(phenylamino) ethyl) picolinamide (5a)

FT- IR (KBr) V_max cm^-1: 3379, 2887, 1653, 1385, 1277, 1018, 785; ¹H NMR (CDCl₃, 400 MHz) δ: 10.09 (brs, 1H, NH), 8.98 (brs, 1H, NH), 8.70 (d, 1H), 8.05 (d, 1H), 8.02 (d, 1H), 7.64 (d, 3H), 7.58 (d, 2H), 7.29 (t, 1H), 4.15 (s, 2H); ¹³C NMR (100MHz, CDCl₃) δ: 167.8, 164.5, 149.0, 130.5, 129.2, 129.1, 127.2, 123.7, 122.3, 119.6, 119.4, 43.9; MS: m/z: 255 (M^+NA); Anal. Calcd. for C₁₄H₁₃N₃O₂: C, 65.87; H, 5.13; O, 12.54; Found: C, 65.64; H, 5.07; O, 12.38.

N-(2-((4-methoxyphenyl) amino)-2-oxoethyl) picolinamide (5b)

FT- IR (KBr) V_max cm^-1: 3360, 2871,1644, 1350, 1241, 1011, 745; ¹H NMR (CDCl₃, 400 MHz) δ: 8.79 (brs, 1H, NH), 8.60 (s, 1H), 8.58 (s, 1H), 8.16 (brs, 1H, NH), 7.46 (s, 1H), 7.44 (d, 2H), 6.83 (d, 2H), 6.78 (d, 1H), 4.32 (s, 2H), 3.77 (s, 3H, OCH₃); ¹³C NMR (100MHz, CDCl₃) δ: 167.2, 164.5, 155.6, 152.5, 150.0, 139.6, 132.4, 127.1, 122.3, 121.1, 120.2, 114.3, 55.6, 43.3; MS: m/z: 285 (M⁺¹); Anal. Calcd. for C₁₅H₁₅N₃O₃: C, 63.15; H, 5.30; O, 16.82; Found: C, 62.64; H, 5.22; O, 16.60.

N-(2-oxo-2-(p-tolylamino) ethyl) picolinamide (5c)

FT- IR (KBr) V_max cm^-1: 3354, 2734, 1567, 1299, 1199, 1005, 757; ¹H NMR (CDCl₃, 400 MHz) δ: 8.80 (brs, 1H, NH), 8.63 (d, 1H), 8.58 (d, 1H), 8.01 (brs, 1H, NH), 7.88 (d, 1H), 7.44 (d, 2H), 7.26 (d, 2H), 7.07 (d, 1H), 4.32 (s, 2H), 2.29 (s, 3H, CH₃); ¹³C NMR (100MHz, CDCl₃) δ: 167.5, 164.5, 150.0, 149.0, 138.3, 136.8, 132.6, 129.6, 127.1, 122.3, 119.6, 43.3, 20.8; MS: m/z: 269 (M^+NA); Anal. Calcd. for C₁₅H₁₅N₃O₂: C, 66.90; H, 5.61; O, 11.88; Found: C, 66.64; H, 5.47; O, 11.68.

RESULTS AND DISCUSSION:

The synthesized compound is depicted in Scheme 1. Initially, 2-(picolinamido) acetic acid (4a) was prepared by the reaction of 2-picolinic acid (1a) and ethyl 2-aminoacetate (2a) was dissolved in acetonitrile in the presence of triethylamine was added as a catalyst TBTU. To afford the ethyl 2-(picolinamido) acetate (3a). The ethyl 2-(picolinamido) acetate (3a) in the presence of base sodium hydroxide in methanol to afford the 2-(picolinamido) acetic acid (4a) in very good yields.

Scheme 1: Preparation of 2-(picolinamido) acetic acid

The one-pot reaction of 2-(picolinamido) acetic acid (4a) was dissolved in acetonitrile solution, TBTU and triethylamine was added and the reaction was stirred at room temperature. Claisen-Schmidt condensation to afford the N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives (5a-c) in very good to excellent yields (scheme-2).

Scheme 2: Preparation of N-(2-oxo-2-(phenylamino)ethyl) picolinamide derivatives

Ultraviolet Visible Spectral Analysis

The UV-Visible spectrum was calculated by the time-dependent (TD)-DFT method for the optimized structure using B3LYP/6-311þþG. The observed electronic absorption is 240nm. The calculated electronic absorption is identified as 241nm. The experimental and theoretical absorption spectrums are represented in Fig-1. The calculated the absorption wavelength using HOMO and LUMO energies. The calculated wavelength is identified as 237 and 294nm.

Fig 1 UV Spectrum of synthesized (5a-c) compound

FT-IR Spectrum:

The FT-IR spectroscopy studies were effectively used to identify the functional groups present in the synthesized N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives. In the range of 400-4000 cm^-1, the various bands obtained in FT-IR spectrum by using KBr pellet technique are shown in figure 2. The absorption band at 3379cm^-1 indicates the presence of carboxamide NH. The stretching vibrations are observed at 2887cm^-1 indicates the presence of aromatic CH units. The sharp absorption band at 1653cm^-1 indicates the presence of a carboxamide carbonyl unit. The absorption band at 1385cm^-1 indicates the presence of the C=N unit which is present in the quinoline moiety. The C-N stretching vibrations are observed at 1277cm^-1 and C-O stretching vibration are observed at 1018cm^-1. The C-H bending vibrations are observed at 785cm^-1.

Fig 2 FT-IR Spectrum of synthesized (5a-c) compound

Biological Studies:

Anti-inflammatory Activity (BSA denaturation technique):

The in vitro anti-inflammatory activity was tested by the protein denaturation technique using bovine serum albumin method⁴².

The standard diclofenac sodium was screened for anti-inflammatory activity by using the inhibition of albumin denaturation technique. The standard drug and compound were dissolved in minimum quantity of dimethyl formamide (DMF) and diluted with phosphate buffer (0.2 M, PH 7.4). The final concentration of DMF in all solution was less than 2.5%. Test Solution (2.5ml) containing different concentrations of the drug was mixed with 1ml of 1mM Bovine serum albumin solution in phosphate buffer and incubated at 37⁰C in an incubator for 10min. Denaturation was induced by keeping the reaction mixture at 70⁰C in a water bath for 10min. After cooling, the turbidity was measured at 660nm. Percentage of Inhibition of denaturation was calculated from control where no drug was added. The percentage inhibition of both the denaturation techniques was calculated by using the following formula and the % inhibition is represented in Fig. 3.

The process of protein denaturation, the proteins’ original structure by the external stress. The denaturation of proteins is the cause of losing their biological function which leads to inflammation. The inhibit protein denaturation was studied. Two different protein denaturation techniques like bovine serum albumin (BSA) and Egg albumin denaturation techniques were studied. The denaturation of protein was tested with various concentrations (10, 50, 100, 250 and 500μM). In the BSA denaturation technique, the 5a, 5b and 5c showed good inhibition and results were nearer to standard. The Egg albumin denaturation technique also exhibited similar results as the BSA denaturation technique. Compare to BSA denaturation activity, the N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives exhibited good activity in egg albumin denaturation study (Fig. 3).

Fig 3 Anti-inflammatory activity of synthesized compound with standard diclofenac

Antidiabetic Activity:

α- Amylase Inhibition Technique:

The antidiabetic activity of the samples was performed using α-amylase inhibition method. Briefly, amylase (0.2%) was incubated with and without samples (in 1.5ml) and standard for 10 min at 25⁰C. This experiment was performed in 0.2M phosphate buffer (pH 6.9). After pre incubation, the 1% starch solution (0.5ml) was added and the reaction mixture was incubated for 30 min at 25⁰C. In order to stop the enzymatic reaction, DNSA reagent (0.5ml) was added as the color reagent and then incubated in a boiling water bath for 90 min. After cooling down to the room temperature, 0.5ml of samples were diluted to 2.5ml of l distilled water and the absorbance measured at 540nm using a UV-Visible spectrophotometer. The measured absorbance was compared with that of the control experiment. The percentage inhibition was calculated from the given formula. (Fig 4)

The α-amylase is responsible for the digestion of starch which breaks down the starch to glucose units. The inhibition of α-amylase lead to the reduction of postprandial hyperglycemia in diabetic conditions. Were studied for their antidiabetic activity using α-amylase inhibition method. The inhibition of amylase is tested with various concentrations of complexes (10, 25, 50, 100 and 200 μM). The percentage inhibition of the all concentrations than standard acarbose. The N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives also showed good α-amylase inhibitory activity in standard acarbose were represented in Fig 4.

Fig 4 Anti-diabetic activity of synthesized compound with standard acarbose

Molecular Docking Study:

Molecular docking of synthesized compound into the α-amylase, COX-1, COX-2 was carried out using the Auto-Dock software (version 4.2). Three dimensional structures of synthesized derivatives were constructed using chem. Bio 3D ultra 13.0 software and then they were energetically minimized by using MMFF94 with 5000 iterations and minimum RMS gradient of 0.10. The crystal structure of α-amylase, COX-1, COX-2 and BSA (1HNY.pdb, 1PGG.pdb and 4COX.pdb) were taken from Protein Data bank. All bound water and ligand were eliminated from the protein and polar hydrogen was added. Moreover, all docking a grid box size of 60x60x60 points in X, Y and Z direction.

5a formed one hydrogen bonds with amino acid residue (ASP197) with corresponding bond distances of 1.91 A, 5b formed one hydrogen bonds with amino acid residue (THR6) with corresponding bond distances of 2.90 A, 5c formed one hydrogen bonds with amino acid residue (SER345) with corresponding bond distances of 2.69 A, corresponding interaction of designed compounds against α-amylase enzyme (1HNY) as shown in table 2 given below (Fig: 5).

Table 2: Molecular docking interaction of designed compounds against α-amylase enzyme (1HNY)

Compounds	Docking score (KJ/mol)	Number of hydrogen bonds	Interacting residues of 1HNY
5a	-249.34	1	ASP197 (1.91Å)
5b	-272.07	1	THR6 (2.90Å)
5c	-255.36	1	SER345(2.69Å)

Docking of 5a with 1HNY

Docking of 5b with 1HNY

Docking of 5c with 1HNY

Fig 5 Molecular docking interaction of designed compounds against α-amylase enzyme (1HNY)

5a formed one hydrogen bonds with amino acid residue (THR212) with corresponding bond distances of 2.98 A, 5b formed one hydrogen bonds with amino acid residue (ARG83) with corresponding bond distances of 2.51 A, 5c formed two hydrogen bonds with amino acid residue (GLN192 and GLN351) with corresponding bond distances of 2.75 A, 2.89 A, corresponding interaction of designed compounds against cyclooxygenase-1 enzyme (1PGG) as shown in table 3 given below (Fig: 6).

Table 3: Molecular docking interaction of designed compounds against cyclooxygenase-1 enzyme (1PGG)

Compounds	Docking score (KJ/mol)	Number of hydrogen bonds	Interacting residues of 1PGG
5a	-246.55	1	THR212 (2.98Å)
5b	-258.82	1	ARG83(2.51Å)
5c	-273.10	2	GLN192(2.75Å), GLN351(2.89Å)

Docking of 5a with 1PGG

Docking of 5b with 1PGG

Docking of 5c with 1PGG

Fig 6 Molecular docking interaction of designed compounds against cyclooxygenase-1 enzyme (1PGG)

5a formed five hydrogen bonds with amino acid residue (TYR130, GLN461, ARG469, ARG44 and ARG44) with corresponding bond distances of 3.21 A, 2.55 A, 3.26 A, 3.33 A, 3.74 A, 5b formed one hydrogen bonds with amino acid residue (GLY135) with corresponding bond distances of 2.92 A, 5c formed two hydrogen bonds with amino acid residue (GLY135) with corresponding bond distances of 2.76 A, corresponding interaction of designed compounds against cyclooxygenase-2 enzyme (4COX) as shown in table 4 given below (Fig: 7).

Table 4: Molecular docking interaction of designed compounds against cyclooxygenase-2 enzyme (4COX)

Compounds	Docking score (KJ/mol)	Number of hydrogen bonds	Interacting residues of 1PGG
5a	-269.28	5	TYR130(3.21Å), GLN461(2.55Å), ARG469(3.26Å), ARG44(3.33Å), ARG44(3.74Å)
5b	-269.36	1	GLY135(2.92Å)
5c	-226.87	1	GLY135(2.76Å)

Docking of 5a with 4cox

Docking of 5b with 4cox

Docking of 5c with 4cox

Fig 7 Molecular docking interaction of designed compounds against cyclooxygenase-2 enzyme (4COX)

Computational Study:

Frontier Molecular Orbital’s:

Highest occupied molecular orbital and lowest unoccupied molecular orbital are used to predict the electrical properties, chemical properties, biological activity, stability and reactivity of the compounds^43,44. The molecular orbital’s an important role in calculating the HOMO, LUMO, band gap and other parameters.

The computational calculations including representation of HOMO, LUMO, molecular electrostatic potential (MEP) and mulliken population analysis (MPA) in the checkpoint files was developed with the Gaussian 09W program using by DFT methods. The chemical structure of the QCKs was optimized with B3LYP/6-31G basis set. The Gauss view was used to visualize the computed structures including frontier molecular orbitals, MEP, MPA representation.

The negative energies of HOMO 5a, 5b and 5c (-5.9863 to -6.2767eV) and LUMO (-1.4743 to -1.5298eV) indicate the stable molecules. The band gap values of the range of 4.456eV - 4.802 eV correspondingly. The calculated band gap of compound 5a is higher than others which are more stable than 5b and 5c. The electrophilicity index (u) is the ability of the molecule to accept the electrons from the environment. Especially, the higher value of electrophilicity index has a higher ability to accept electrons from bimolecular.

The results suggested the compound 5c exhibited higher electrophilicity index than others. The calculated electrophilicity index is found to be 3.1691eV which represented the highest capacity to accept the electrons. Molecular geometry parameters such as bond length, bond angle and dihedral angle were calculated and presented in Table 5. The optimized structures of complexes were given in Fig. 8 & 9.

Fig 8 Homo Study of Synthesized Compound

Fig 9 LUMO Study of synthesized compound

Molecular Electrostatic Potential (MEP):

Molecular electrostatic potential the region of electrophilic and nucleophilic sites of the molecules. The different colors in MEP are indicated different values of the electrostatic potential. Red, blue and green colour indicates the electrophilic, nucleophilic reactivity and zero electrostatic potential respectively. The blue indicates the strongest attraction and the red indicates the strongest repulsion. In molecular electrostatic potential, the negative potential has been used to identify the binding region of the ligand for the interaction of biomolecule. The synthesized compound the most negative potential is located at the carbonyl of carboxamide ring. In synthesized compound the negative potential is located at pyridine ring and carbonyl of carboxamide. Overall, the negative potential is placed on the carbonyl, pyridine ring. These regions may responsible for the formation of hydrogen bonding interaction with a biomolecule. The pictorial representation of MEP was given in Fig. 10.

Fig 10 Molecular Electrostatic Potential (Mep) Study of Synthesized Compound

Fig 11 Optimize Structure for N-(2-oxo-2-(phenylamino)ethyl) picolinamide derivatives

CONCLUSION:

The synthesis of N-(2-oxo-2-(phenylamino)ethyl) picolinamide promoted by TBTU triethylamine as catalyst in acetonitrile medium and reaction was stirred at room temperature in good yields. The synthesized N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives (5a-c) were screened for anti-inflammatory activity exhibited madrate activity with diclofenac sodium as a reference drug. The synthesized N-(2-oxo-2-(phenylamino) ethyl) picolinamide derivatives (5a-c) were screened for antidiabetic activity exhibited good activity with acarbose as a standard drug. The molecular docking results showed that the corresponding interaction of designed compounds against α-amylase enzyme (1HNY) 5a formed one hydrogen bonds with amino acid residue (ASP197) with corresponding bond distances of 1.91 A, 5b formed one hydrogen bonds with amino acid residue (THR6) with corresponding bond distances of 2.90 A, 5c formed one hydrogen bonds with amino acid residue (SER345) with corresponding bond distances of 2.69 A. Corresponding interaction of designed compounds against cyclooxygenase-1 enzyme (1PGG) 5a formed one hydrogen bonds with amino acid residue (THR212) with corresponding bond distances of 2.98 A, 5b formed one hydrogen bonds with amino acid residue (ARG83) with corresponding bond distances of 2.51 A, 5c formed two hydrogen bonds with amino acid residue (GLN192 and GLN351) with corresponding bond distances of 2.75 A, 2.89 A. Corresponding interaction of designed compounds against cyclooxygenase-2 enzyme (4COX) 5a formed five hydrogen bonds with amino acid residue (TYR130, GLN461, ARG469, ARG44 and ARG44) with corresponding bond distances of 3.21 A, 2.55 A, 3.26 A, 3.33 A, 3.74 A, 5b formed one hydrogen bonds with amino acid residue (GLY135) with corresponding bond distances of 2.92 A, 5c formed two hydrogen bonds with amino acid residue (GLY135) with corresponding bond distances of 2.76 A. All the computational calculations including representation of HOMO, LUMO, molecular electrostatic potential (MEP). The negative energies of HOMO 5a, 5b and 5c (-5.9863 to -6.2767eV) and LUMO (-1.4743 to -1.5298eV) indicate the stable molecules. The band gap values of the range of 4.456eV - 4.802eV correspondingly. The calculated band gap of compound 5a is higher than others which are more stable than 5b and 5c. The results suggested that the compound 5c exhibited higher electrophilicity index than others. The calculated electrophilicity index is found to be 3.1691eV which represented the highest capacity to accept the electrons.

DECLARATION OF COMPETING INTEREST:

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

REFERENCES:

1. Rahman MA. Chalcone: A valuable insight into the recent ad into the recent advances hand potential pharmacological activities. Chem Sci J. 2011.

2. Henry GD. Palladium-Catalyzed Sonogashira Coupling Reaction of 2-Amino-3-Bromopyridines with Terminal Alkynes. Tetrahedron, 2004; 60: 6043-6061.

3. Szliszka E, Czuba ZP, Mazur B, Sedek L, Paradysz A, Krol W. Chalcones enhance TRAIL-induced apoptosis in prostate cancer cells. Int J Mol Sci. 2009; 11(1): 1-13.

4. Hideo K, Tatsurou K, Yoko H. Kojima. Chem. Abstr. 1997; 25: 126.

5. Abbas A, Naseer MM, Hasan A, Hadda TB. Synthesis and Cytotoxicity Studies of 4-Alkoxychalcones as New Antitumor Agents. J. Mater. Environ. Sci. 2014; 5(1): 281-292.

6. Grosscurt AC, Van HR, Wellinga K. 1-Phenylcarbamoyl-2-pyrazolines, a new class of insecticides. 3. Synthesis and insecticidal properties of 3,4-diphenyl-1-phenylcarbamoyl-2-pyrazolines. J. Agric. Food Chem. 1979; 27(2): 406-409.

7. Tanaka H, Nakamura S, Onda K, Tazaki T, Hirano T.Sofalcone, an anti-ulcer chalcone derivative, suppresses inflammatory crosstalk between macrophages and adipocytes and adipocyte differentiation: Implication of heme-oxygenase-1 induction. Biochem. Biophys. Res. Commun. 2009; 381: 566-571.

8. Takahashi M, Maeda S, Ogura K, Terano A, Omata M. The Possible Role of Vascular Endothelial Growth Factor (VEGF) in Gastric Ulcer Healing Effect of Sofalcone o VEGF Release in Vitro. J. Clin. Gastroenterol. 1998; 27(1): 178-182.

9. Real L, David C, Francois B. Can J. Pharm. Sci., 1967; 2: 37.

10. Nitin GG, Rajput PR, Banewar VW, Raut AR. Synthesis and antimicrobial activity of some chalcones and flavones having 2-hydroxy acetophenone moiety. Int. J. Pharm. Bio. Sci. 2012; 3(3): 389-395.

11. Bowden K, Dal PA, Shah CK. Structure-activity relations, Antibacterial activity of a series of substituted (E)-3-(4-phenylbenzoyl) acrylic acids, -chalcones, -2-hydroxy chalcones and -α-bromochalcones; addition of cysteine to substituted 3-benzoylacrylic acids and related compounds. J. Chem. Res. Synop., 1990; 12: 377.

12. Marmo E, Caputi AP, Cataldi S. Experimental investigation of 4-(3',4',5'-trimethoxy cinnamoyl)-1-piperaziny l-pyrrolidinyl maleate (67350): effect on the cardiovascular system and on certain smooth muscles. Farmaco Ed. Prat. 1970; 28(3): 132-160.

13. Ogansyna ET, Khim AH. Farm. 1991; 25(8): 18.

14. Zongru G, Rui H. Chem. Abstr. 1996; 125: 103768.

15. De Vincenzo R, Seambla G, Panici P, Benedess Remelletti FO. Anticancer Drug Des. 1995: 481-490.

16. Hsieh Hasin Kaw, Lee-Tai-Hua Wang, Jih-Pyang Wang. Chem. Abstr. 1998; 128: 225684.

17. Parmar VS, Jain CS. Indian J. Chem., Sect. B., Org. Chem. Incl Med. Chem. 1998; 37B (7): 628-643.

18. Nissan Chemical Industries Ltd., Japan Kokai Tokkyo Koho Japan 3808035, 1983.

19. Gross Curt AC, Van HR, Wellinga K. J. Agric. Food. Chem. 1979; 27(2): 406.

20. Ur Rashid H, Xu Y, Ahmad N, Muhammad Y, Wang L. Promising anti-inflammatory effects of chalcones via inhibition of cyclooxygenase, prostaglandin E2, inducible NO synthase and nuclear factor κb activities, Bioorganic Chemistry. 2019; 87: 335−365.

21. Nurkenov O, Ibraev M, Schepetkin I, Khlebnikov A, Seilkhanov T, Arinova A, Isabaeva M. Synthesis, structure, and anti-inflammatory activity of functionally substituted chalcones and their derivatives, Russian Journal of General Chemistry. 2019; 89(7): 1360−1367.

22. Ibrahim TS, Moustafa AH, Almalki AJ, Allam RM, Althagafi A, Md, S, Mohamed MF. Novel chalcone/aryl carboximidamide hybrids as potent anti-inflammatory via inhibition of prostaglandin E2 and inducible NO synthase activities: design, synthesis, molecular docking studies and ADMET prediction, Journal of Enzyme Inhibition and Medicinal Chemistry. 2021; 36 (1): 1067−1078.

23. Lakshminarayanan B, Kannappan N, Subburaju T. Synthesis and biological evaluation of novel chalcones with methanesulfonyl end as potent analgesic and anti-inflammatory agents, Int. J. Pharmaceutical Res. Biosci. 2020; 11(10): 4974−4981.

24. Higgs J, Wasowski C, Marcos A, Jukic M, Pavan CH, Gobec S, de Tezanos Pinto F, Colettis N, Marder M. Chalcone derivatives: synthesis, in vitro and in vivo evaluation of their antianxiety, anti-depression and analgesic effects, Heliyon. 2019; 5(3): e01376.

25. Bale AT, Salar U, Khan KM, Chigurupati S, Fasina T, Ali F, Ali M, Nanda SS, Taha M, Perveen S. Chalcones and Bis-Chalcones Analogs as DPPH and ABTS Radical Scavengers, Letters in Drug Design & Discovery. 2021; 18(3): 249−257.

26. Al Zahrani NA, El-Shishtawy RM, Elaasser MM, Asiri AM. Synthesis of novel chalcone -based phenothiazine derivatives as antioxidant and anticancer agents. Molecules. 2020; 25(19): 4566.

27. Qin HL, Zhang ZW, Lekkala R, Alsulami H, Rakesh K. Chalcone hybrids as privileged scaffolds in antimalarial drug discovery: a key review. European Journal of Medicinal Chemistry. 2020; 193: 112215.

28. Fu Y, Liu D, Zeng H, Ren X, Song BHD, Gan X. New chalcone derivatives: Synthesis, antiviral activity and mechanism of action. RSC Advances. 2020; 10(41): 24483−24490.

29. Alsafi MA, Hughes DL, Said MA, First COVID-19 molecular docking with a chalcone-based compound: synthesis, single-crystal structure and Hirshfeld surface analysis study. Acta Crystallogr, Sect. C: Structural Chemistry. 2020; 76(12): 1043−1050.

30. Duran N, Polat MF, Aktas DA, Alagoz MA, Ay E, Cimen F, Tek E, Anil B, Burmaoglu S, Algul O. New chalcone derivatives as effective against SARS-CoV-2 agent. Int. J. Clin. Pract. 2021: e14846.

31. Kalirajan R. Activity of some novel chalcone substituted 9-anilinoacridines against coronavirus (COVID-19): a computational approach. Corona viruses. 2020: 13−22.

32. Welday Kahssay S, Hailu GS, Taye Desta K, Design, Synthesis, Characterization and in vivo Antidiabetic Activity Evaluation of Some Chalcone Derivatives. Drug Design, Development and Therapy. 2022; 15: 3119.

33. Jain A, Jain D. Synthesis, characterization and biologicalevaluation of some new heterocyclic derivatives of chalcone as antihyperglycemic agents. Int. J. Pharmaceutical Sci. Res. 2019; 59: 5700−5706.

34. Kozłowska J, Potaniec B, Baczyńska D, Żarowska B, Anioł M. Synthesis and Biological Evaluation of Novel Aminochalcones as Potential Anticancer and Antimicrobial Agents. Molecules. 2019; 24(22): 4129; doi: 10.3390/molecules24224129.

35. Rioux B, Pinon A, Gamond A, Martin F, Laurent A, Champavier Y, Barette C, Liagre B, Fagnère C, Sol V, Pouget C. Synthesis and biological evaluation of chalcone-polyamine conjugates as novel vectorized agents in colorectal and prostate cancer chemotherapy. European Journal of Medicinal Chemistry. 2021; 222: 113586; doi: 10.1016/j.ejmech.2021.113586.

36. Lu CF, Wang SH, Pang XJ, Zhu T, Li HL, Li QR, Li QY, Gu YF, Mu ZY, Jin MJ, Li YR, Hu YY, Zhang YB, Song J, Zhang SY, Synthesis and Biological Evaluation of Amino Chalcone Derivatives as Antiproliferative Agents. Molecules. 2020; 25(23): 5530; doi: 10.3390/molecules25235530.

37. Modi SR, Naik HB. Orient J. Chem., 1994; 10(1): 85-86.

38. Siger A, Czubinski J, Kachlicki P, Dwiecki K, Lampart-Szczapa E, Nogala-Kalucka AM. Antioxidant activity and phenolic content in three lupin species. J Food Compos A al. 2012; 25(2): 190-7.

39. Echeverria C, Santibanez JF, Donoso-Tauda O, Escobar CA, Ramirez-Tagle R. Structural antitumoral activity relationships of synthetic chalcones. I t J Mol Sci. 2009; 221-31.

40. Rahman MA. Chalcone: A valuable insight into the recent advances and potential pharmacological activities. Chem Sci J. 2011.

41. Selvakumar N, Kumar GS, Azhagan AM, Rajulu GG, Sharma S, Kumar MS. Synthesis, SAR and antibacterial studies on novel chalcone oxazolidinone hybrids. Eur J Med Chem. 2007; 42(4): 538-43.

42. Sribalan R, Banuppriya G, Kirubavathi M, Jayachitra A, Padmini V. Multiple biological activities and molecular docking studies of newly synthesized 3-(pyridin-4-yl)-1H-pyrazole-5-carboxamide chalcone, Bioorg. Med. Chem. Lett. 2016; 26: 5624-5630.

43. Sarojinidevi K, Subramani P, Jeeva M, Sundaraganesan N, Boobalan MS, Prabhu GV. Synthesis, molecular structure, quantum chemical analysis, spectroscopic and molecular docking studies of N-(Morpholinomethyl) succinimide using DFT method. J. Mol. Struct. 2018; 1175: 609-623.

44. Shafieyoon P, Mehdipour E, Mary YS. Synthesis, characterization and Biological Investigation of glycine- based sulfonamide derivative and its complex: vibration assignment, HOMO and LUMO analysis, MEP and molecular docking. J. Mol. Struct. 2019; 1181: 244-252.

Received on 31.10.2024 Revised on 20.12.2024

Accepted on 27.01.2025 Published on 24.02.2025

Available online from February 27, 2025

Asian J. Research Chem.2025; 18(1):17-26.

DOI: 10.52711/0974-4150.2025.00004

This work is licensed under a Creative Commons Attribution-Non Commercial-Share Alike 4.0 International License. Creative Commons License.

S. No	2-(picolinamido)acetic acid	Time ^a (h/min)	Yield^b(%)	N-(2-oxo-2-(phenylamino)ethyl)picolinamide
1	(4a)	4.0h	88.0	(5a)
2	(4a)	4.5h	92.0	(5b)
3	(4a)	5.0h	87.0	(5c)

S. No	Compound Name	HOMO	LUMO	Band gap(DE)	Chemical potential	Global hardness	Global softness	Electrophilicity index
1	5a	-6.2767	-1.4743	4.802	-3.8755	2.4011	0.2082	3.1275
2	5b	-5.7692	-1.4468	4.322	-3.6080	2.1611	0.2313	3.0117
3	5c	-5.9863	-1.5298	4.456	-3.7581	2.2282	0.2243	3.1691